scholarly journals A MATHEMATICAL MODEL OF GALVANIC CORROSION UNDER THE CONDITIONS OF A THIN ELECTROLYTE FILM

2016 ◽  
Vol 56 (2) ◽  
pp. 106-111
Author(s):  
Vít Jeníček ◽  
Linda Diblíková
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Time Dependence ◽  
Experimental Error ◽  
Atmospheric Corrosion ◽  
Galvanic Corrosion ◽  
Experimental Results ◽  
Polarization Curves ◽  
Electrolyte Film ◽  
The Difference

<p>A mathematical model of galvanic corrosion under the conditions of a thin electrolyte film was used to evaluate atmospheric corrosion. Experimentally determined weight loss values were used to validate the modelled results. The time dependence of the corrosion degradation was included in the model using polarization curves of the corroded materials. The difference between the modelled results and the experimental results was 20%, taking the experimental error into account.</p>

A Mathematical Model of Some Aspects of Fish Growth, Respiration, and Mortality

1967 ◽  
Vol 24 (11) ◽  
pp. 2355-2453 ◽  
Author(s):  
Erik Ursin
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Metabolic Model ◽  
The Body ◽  
Fish Growth ◽  
Natural Mortality ◽  
Gill Area ◽  
Growth Respiration ◽  
The Difference

A simple metabolic model describing growth as the difference between what enters the body and what leaves it, is elaborated assuming that synthetic processes (the building-up, the anabolism) are consuming energy supplied by processes of decomposition (the break-down, the catabolism). This leads to partitioning total catabolism into two components, one being a function of the rate of synthesis, another keeping the body functioning independently of synthesis. The rate of synthesis is described as a function of food taken, of the efficiencies of digestion and energy conversion, and of the absorbing surface of the intestine. Catabolic processes are supposed to be functions of the oxygen concentration in the water, the absorbing surface of the gills, and the rate of oxygen transport. Both kinds of processes are made functions of temperature in the way enzymatic processes usually are. Assuming that molecular interactions accidentally go wrong makes natural mortality, like growth, a function of the rates of anabolic and catabolic processes and body size.Application of the model to data of length-at-age, food and oxygen consumption, weight loss, gill area, and natural mortality indicates that at least some of the main hypotheses cannot be rejected on available evidence.

scholarly journals Modeling for Pyrolysis of Solid Biomass

2019 ◽  
Vol 64 (2) ◽  
pp. 192-204
Author(s):  
Biljana Miljkovic ◽  
Branislava Nikolovski ◽  
Dejan Mitrović ◽  
Jelena Janevski
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Weight Loss ◽  
Degradation Mechanism ◽  
Volatile Matter ◽  
Point Of View ◽  
Experimental Results ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Simulation Results

In comparison to coal, biomass is characterized by a higher content of volatile matter. It is a renewable source of energy which has many advantages from an ecological point of view. Understanding the physical phenomena of pyrolysis and representing them with a mathematical model is the primary step in the design of pyrolysis reactors. In the present study, an existing mathematical model is used to describe the pyrolysis of a single solid particle of biomass. It couples the heat transfer equations with the chemical kinetics equations. A finite difference method is used for solving the heat transfer equation and the two-step pyrolysis kinetics equations. The model equation is solved for a slab particle of equivalent dimension 0.001 m and temperature ranging from 300 to 923 K. An original numerical model for the pyrolysis of wood chips is proposed and relevant equations solved using original program realized in MATLAB.To check the validity of the numerical results, experimental results of pyrolysis of woody biomass in laboratory facility was used. The samples were heated over a range of temperature from 300 to 923 K with three different heating rates of 21, 32 and 55 K/min, and the weight loss was measured. The simulation results as well as the results obtained from thermal decomposition process indicate that the temperature peaks at maximum weight loss rate change with the increase in heating rate. The experimental results showed that the simulation results are in good agreement and can be successfully used to understand the degradation mechanism of solid reaction.

Simulation and experimentation of a magnetorheological brake with adjustable gap

2016 ◽  
Vol 28 (12) ◽  
pp. 1614-1626 ◽  
Author(s):  
Wan-Li Song ◽  
Dong-Heng Li ◽  
Yan Tao ◽  
Na Wang ◽  
Shi-Chao Xiu
Keyword(s):  
Magnetorheological Fluid ◽  
Structure Design ◽  
Experimental Results ◽  
Wear Property ◽  
Braking Performance ◽  
Braking Torque ◽  
The Difference ◽  
The Impact ◽  
Theoretical Analyses ◽  
Magnetostatic Simulation

The aim of this work is to investigate the effect of the small magnetorheological fluid gap on the braking performance of the magnetorheological brake. In this article, theoretical analyses of the output torque are given first, and then the operating principle and design details of the magnetorheological brake whose magnetorheological fluid gap can be altered are presented and discussed. Next, the magnetic circuit of the proposed magnetorheological brake is conducted and further followed by a magnetostatic simulation of the magnetorheological brakes with different sizes of fluid gap. A prototype of the magnetorheological brake is fabricated and a series of tests are carried out to evaluate the braking performance and torque stability, as well as the verification of the simulation results. Experimental results show that the braking torque increases with the increase in the current, and the difference for the impact of the fluid gap on braking performance is huge under different currents. The rules, which the experimental results show, have an important significance on both the improvement of structure design for magnetorheological brake and the investigation of the wear property under different fluid gaps.

Friction and Tribological Considerations for Nanometer Range Machining

2001 ◽  
Author(s):  
Som Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
High Precision ◽  
Local Deformation ◽  
Experimental Results ◽  
Precision Machining ◽  
Complex Motion ◽  
Positioning Accuracy ◽  
Nanometer Range ◽  
Motion Characteristic ◽  
Low Speeds

Abstract Positioning accuracy within the range of nanometers is required for high precision machining applications. The implementation of such a range is difficult through the slides because of (a) irregular nature of friction at the slider-guideway interface, and (b) complex motion characteristic at very low speeds. The complexity arises due to the local deformation at the interface prior to breakaway, which is known as microdynamics. In this work prior experimental results exhibiting microdynamics have been appraised, and mathematical model developed to understand this behavior.

Design and Experimental Analysis of Novel Refractometer Based on Photoelectric Sensor Technology

2011 ◽  
Vol 383-390 ◽  
pp. 5211-5215
Author(s):  
Yin Lin Li ◽  
Zhong Hua Huang ◽  
Kai Bo Hu
Keyword(s):  
Mathematical Model ◽  
Experimental Analysis ◽  
Differential Method ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Sensor Technology ◽  
Photoelectric Sensor ◽  
Better Than

A novel refractometer based on photoelectric sensor technology and differential method is proposed. Sensing principle and mathematical model are introduced; structure and key parameters of sensing probe are designed through detail calculation. Theoretical solution shows resolution reaches order of 10-5. Preliminary experiments verify the feasibility of the design, experimental results show stability error better than ±1.02×10-4, error caused by temperature is 6.65×10-6/°C.

An Improved Trace Method for Moving Target under Occlusion

2014 ◽  
Vol 672-674 ◽  
pp. 1931-1934
Author(s):  
Yu Bing Dong ◽  
Guang Liang Cheng ◽  
Ming Jing Li
Keyword(s):  
Mathematical Model ◽  
Target Tracking ◽  
Difficult Problem ◽  
Block Matching ◽  
Experimental Results ◽  
Polar Coordinates ◽  
Moving Target ◽  
Trajectory Prediction ◽  
Tracking Method

Occlusion is a difficult problem to be solved in the process of target tracking. In order to solve the problem of occlusion, a new tracking method combined with trajectory prediction and multi-block matching is presented and studied,and a mathematical model of trajectory prediction of moving target is established in polar coordinates and verified through some experiments. The experimental results show that the new tracking method can be better to trace and forecast the moving target under occlusion.

Impact of multilayered compression bandages on sub-bandage interface pressure: a model

2011 ◽  
Vol 26 (2) ◽  
pp. 75-83 ◽  
Author(s):  
J Al Khaburi ◽  
E A Nelson ◽  
J Hutchinson ◽  
A A Dehghani-Sanij
Keyword(s):  
Mathematical Model ◽  
Thick Wall ◽  
Compression Bandage ◽  
Leg Ulcers ◽  
Interface Pressure ◽  
Venous Leg Ulcers ◽  
Compression Bandages ◽  
Thick Cylinder ◽  
The Difference ◽  
Interface Pressures

Background Multi-component medical compression bandages are widely used to treat venous leg ulcers. The sub-bandage interface pressures induced by individual components of the multi-component compression bandage systems are not always simply additive. Current models to explain compression bandage performance do not take account of the increase in leg circumference when each bandage is applied, and this may account for the difference between predicted and actual pressures. Objective To calculate the interface pressure when a multi-component compression bandage system is applied to a leg. Method Use thick wall cylinder theory to estimate the sub-bandage pressure over the leg when a multi-component compression bandage is applied to a leg. Results A mathematical model was developed based on thick cylinder theory to include bandage thickness in the calculation of the interface pressure in multi-component compression systems. In multi-component compression systems, the interface pressure corresponds to the sum of the pressures applied by individual bandage layers. However, the change in the limb diameter caused by additional bandage layers should be considered in the calculation. Adding the interface pressure produced by single components without considering the bandage thickness will result in an overestimate of the overall interface pressure produced by the multi-component compression systems. At the ankle (circumference 25 cm) this error can be 19.2% or even more in the case of four components bandaging systems. Conclusion Bandage thickness should be considered when calculating the pressure applied using multi-component compression systems.

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